package lab02.test36;

public class Postgraduate extends Student {
    @Override
    String calGrade(){

       //成绩等级
       String grade = "";
       double avg = average();

        if (avg >= 90 && avg <= 100)
            grade = "优秀";
        else if (avg >= 80 && avg < 90)
            grade = "良好";
        else if (avg >= 70 && avg < 80)
            grade = "一般";
        else if (avg >= 60 && avg < 70)
            grade = "及格";
        else
            grade = "不及格";
        return grade;

          }
   }
